A tetrose is a monosaccharide with 4 carbon atoms. They have either an aldehyde functional group in position 1 (aldotetroses) or a ketone functional group in position 2 (ketotetroses).
Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH2C(O)CH2OPO32-. This anion is involved in many metabolic pathways, including the Calvin cycle in plants and glycolysis. It is the phosphate ester of dihydroxyacetone.
Methylotrophs are a diverse group of microorganisms that can use reduced one-carbon compounds, such as methanol or methane, as the carbon source for their growth; and multi-carbon compounds that contain no carbon-carbon bonds, such as dimethyl ether and dimethylamine. This group of microorganisms also includes those capable of assimilating reduced one-carbon compounds by way of carbon dioxide using the ribulose bisphosphate pathway. These organisms should not be confused with methanogens which on the contrary produce methane as a by-product from various one-carbon compounds such as carbon dioxide. Some methylotrophs can degrade the greenhouse gas methane, and in this case they are called methanotrophs. The abundance, purity, and low price of methanol compared to commonly used sugars make methylotrophs competent organisms for production of amino acids, vitamins, recombinant proteins, single-cell proteins, co-enzymes and cytochromes.
Transketolase is an enzyme that, in humans, is encoded by the TKT gene. It participates in both the pentose phosphate pathway in all organisms and the Calvin cycle of photosynthesis. Transketolase catalyzes two important reactions, which operate in opposite directions in these two pathways. In the first reaction of the non-oxidative pentose phosphate pathway, the cofactor thiamine diphosphate accepts a 2-carbon fragment from a 5-carbon ketose (D-xylulose-5-P), then transfers this fragment to a 5-carbon aldose (D-ribose-5-P) to form a 7-carbon ketose (sedoheptulose-7-P). The abstraction of two carbons from D-xylulose-5-P yields the 3-carbon aldose glyceraldehyde-3-P. In the Calvin cycle, transketolase catalyzes the reverse reaction, the conversion of sedoheptulose-7-P and glyceraldehyde-3-P to pentoses, the aldose D-ribose-5-P and the ketose D-xylulose-5-P.
Alkylglycerone phosphate synthase is an enzyme associated with Type 3 Rhizomelic chondrodysplasia punctata. This enzyme catalyses the following chemical reaction
D-Xylulose 5-phosphate (D-xylulose-5-P) is an intermediate in the pentose phosphate pathway. It is a ketose sugar formed from ribulose-5-phosphate by ribulose-5-phosphate epimerase. In the non-oxidative branch of the pentose phosphate pathway, xylulose-5-phosphate acts as a donor of two-carbon ketone groups in transketolase reactions.
Glycerol-3-phosphate dehydrogenase (GPDH) is an enzyme that catalyzes the reversible redox conversion of dihydroxyacetone phosphate to sn-glycerol 3-phosphate.
Ogataea polymorpha is a methylotrophic yeast with unusual characteristics. It is used as a protein factory for pharmaceuticals.
In enzymology, a methanol dehydrogenase (MDH) is an enzyme that catalyzes the chemical reaction:
In enzymology, a glycerol-3-phosphate oxidase (EC 1.1.3.21) is an enzyme that catalyzes the chemical reaction
The enzyme ketotetrose-phosphate aldolase catalyzes the chemical reaction
The enzyme tagatose-bisphosphate aldolase catalyzes the chemical reaction
The enzyme methylglyoxal synthase catalyzes the chemical reaction
In enzymology, a 1-deoxy-d-xylulose-5-phosphate synthase (EC 2.2.1.7) is an enzyme in the non-mevalonate pathway that catalyzes the chemical reaction
In enzymology, a pyridoxine 5'-phosphate synthase (EC 2.6.99.2) is an enzyme that catalyzes the chemical reaction
6-deoxy-5-ketofructose 1-phosphate synthase is an enzyme with systematic name 2-oxopropanal:D-fructose 1,6-bisphosphate glycerone-phosphotransferase. This enzyme catalyses the following chemical reaction
3-hexulose-6-phosphate synthase is an enzyme with systematic name D-arabino-hex-3-ulose-6-phosphate formaldehyde-lyase (D-ribulose-5-phosphate-forming). This enzyme catalyses the following chemical reaction
Pyridoxal 5′-phosphate synthase (glutamine hydrolysing) (EC 4.3.3.6, PdxST) is an enzyme with systematic name D-ribose 5-phosphate,D-glyceraldehyde 3-phosphate pyridoxal 5′-phosphate-lyase. This enzyme catalyses the following chemical reaction
6-phospho-3-hexuloisomerase is an enzyme with systematic name D-arabino-hex-3-ulose-6-phosphate isomerase. This enzyme catalyses the following chemical reaction
Sulfoglycolysis is a catabolic process in primary metabolism in which sulfoquinovose (6-deoxy-6-sulfonato-glucose) is metabolized to produce energy and carbon-building blocks. Sulfoglycolysis pathways occur in a wide variety of organisms, and enable key steps in the degradation of sulfoquinovosyl diacylglycerol (SQDG), a sulfolipid found in plants and cyanobacteria into sulfite and sulfate. Sulfoglycolysis converts sulfoquinovose (C6H12O8S−) into various smaller metabolizable carbon fragments such as pyruvate and dihydroxyacetone phosphate that enter central metabolism. The free energy is used to form the high-energy molecules ATP (adenosine triphosphate) and NADH (reduced nicotinamide adenine dinucleotide). Unlike glycolysis, which allows metabolism of all carbons in glucose, some sulfoglycolysis pathways convert only a fraction of the carbon content of sulfoquinovose into smaller metabolizable fragments; the remaineder is excreted as C3-sulfonates 2,3-dihydroxypropanesulfonate (DHPS) or sulfolactate (SL); or the C2-sulfonate isethionate.
